The present invention is concerned generally with minimally invasive methods for accessing the vascular system and hollow organs of the body; and is directed to an assembly and methodology for creating sutureless vascular anastomoses and hollow organ communication channels on-demand.
Coronary artery disease is the single leading cause of human mortality and is annually responsible for over 900,000 deaths in the United States alone. Additionally, over 3 million Americans suffer chest pain (angina pectoris) because of it. Typically, the coronary artery becomes narrowed over time by the build up of fat, cholesterol and blood clots. This narrowing of the artery is called arteriosclerosis; and this condition slows the blood flow to the heart muscle (myocardium) and leads to angina pectoris due to a lack of nutrients and adequate oxygen supply. Sometimes it can also completely stop the blood flow to the heart causing permanent damage to the myocardium, the so-called xe2x80x9cheart attack.xe2x80x9d
The conventional treatment procedures for coronary artery disease vary with the severity of the condition. If the coronary artery disease is mild, it is first treated with diet and exercise. If this first course of treatment is not effective, then the condition is treated with medications. However, even with medications, if chest pain persists (which is usually secondary to development of serious coronary artery disease), the condition is often treated with invasive procedures to improve blood flow to the heart. Currently, there are several types of invasive procedures: (1) Catheterization techniques by which cardiologists use balloon catheters, atherectomy devices or stents to reopen up the blockage of coronary arteries; or (2) Surgical bypass techniques by which surgeons surgically place a graft obtained from a section of artery or vein removed from other parts of the body to bypass the blockage.
Conventionally, before the invasive procedures are begun, coronary artery angiography is usually performed to evaluate the extent and severity of the coronary artery blockages. Cardiologists or radiologists thread a thin catheter through an artery in the leg or arm to engage the coronary arteries. X-ray dye (contrast medium) is then injected into the coronary artery through a portal in the catheter, which makes the coronary arteries visible under X-ray, so that the position and size of the blockages in the coronary arteries can be identified. Each year in U.S.A., more than one million individuals with angina pectoris or heart attack undergo coronary angiographies for evaluation of such coronary artery blockages. Once the blocked arteries are identified, the physician and surgeons then decide upon the best method to treat them.
In the surgical correction of vascular disease in the human body, it is frequently necessary to attach blood vessels to each other. A native blood vessel may be diseased with conditions that cause blockages, such as atherosclerosis. In this situation, it is frequently necessary to reroute the blood that would ordinarily traverse the diseased vessel via the creation of a vascular bypass. The conduit used to form this bypass around an obstructed segment may be another blood vessel native to the patient, such as a vein or artery harvested from elsewhere in the body; or may be a man-made conduit of either synthetic or biological material. Methods for attaching blood vessels to each other include: end to end attachments, where the result is a linear conduit for blood flow with the bypassing vessel and the vessel to which it is attached lying in parallel, in-line with each other; side to side attachments, where the result is a staggered, linear channel, where the bypassing vessel and the vessel to which it is attached are in parallel but offset by the width of one of the blood vessels; and end to side attachments, where the bypassing vessel meets the vessel which it is to supply with flow at some angle of less than 180 degrees, and typically approximately 90 degrees and often as a xe2x80x98Txe2x80x99 or xe2x80x98Lxe2x80x99 or xe2x80x98Hxe2x80x99 type of connection.
It is useful here to understand in depth what the traditional coronary arterial bypass entails and demands both for the patient and for the cardiac surgeon. In a standard coronary bypass operation, the surgeon must first make a foot-long incision in the chest and split the breast bone of the patient. The operation requires the use of a heart-lung machine that keeps the blood circulating while the heart is being stopped and the surgeon places and attaches the bypass grafts. To stop the heart, the coronary arteries also have to be perfused with a cold potassium solution (cardioplegia). In addition, the body temperature of the patient is lowered by cooling the blood as it circulates through the heart-lung machine in order to preserve the heart and other vital organs. Then, as the heart is stopped and a heart-lung machine pumps oxygenated blood through the patient""s body, the surgeon makes a tiny opening into the front wall of the target coronary artery with a very fine knife (arteriotomy); takes a previously excised saphenous vein (a vein from a leg) or an internal mammary artery (an artery from the chest); and sews the previously excised blood vessel to the coronary artery. Synthetic substitutes for a naturally occurring blood vessel are available and often used.
To create the anastomosis at the aorta, the ascending thoracic aorta is first partially clamped using a curved vascular clamp to occlude the proper segment of the ascending aorta; and a hole is then created through the front wall of the aorta to anchor the vein graft (or synthetic substitute) with sutures. The graft bypasses the blockage in the coronary artery and restores adequate blood flow to the heart. After completion of the grafting, the patient is taken off of the heart-lung machine and the patient""s heart starts beating again. Most of the patients can leave the hospital in about 6 days after the surgical procedure.
It will be noted that coronary artery bypass surgery is considered a definitive method for treating coronary arterial disease because all kinds of obstructions cannot be treated by angioplasty; and because a recurrence of blockages in the coronary arteries even after angioplasty is not unusual. Also coronary artery bypass surgery usually provides for a longer patency of the grafts and the bypassed coronary arteries in comparison with the results of an angioplasty procedure. However, traditional coronary artery bypass surgery is a far more complicated procedure, having need of a heart-lung machine and a stoppage of the heart. Also, it is a more invasive procedure and is more expensive to perform. Therefore, cardiac surgeons have recently developed an alternative to the standard bypass surgery, namely xe2x80x9cminimally invasive bypass operationxe2x80x9d (MIBO) in order to reduce the risks and the cost associated with the surgery. Also, the MIBO is performed without use of a heart-lung machine or the stopping of the heart. Some of the current methods for creating these connections include handsewn surgical anastomoses, where a surgeon places a series of surgical knots around the circumference of the vascular connection, forming a liquid-tight connection; as well as a variety of vascular staple type devices, where mechanical apparatii are used to effect the connection, generally using a two or more part apparatus comprising the staple introducer and an xe2x80x98anvilxe2x80x99 type of part against which the staples are curved back, bent, or otherwise fixed into position around the circumference of the vascular connection.
Another approach has been the introducer catheter based methods and apparatii for the creation of an end-to-side vascular connection (anastomosis) using an implanted device comprising a deformable flange or retained portion and deformable flange, to which a biological or synthetic conduit has been pre-attached ex-vivo; and a variety of configurations for introducer mechanisms and systems for, inserting this implantable device into the side of the blood vessel. For the purposes of this description, the blood vessel is generally defined as the blood vessel which is punctured and which receives the collar or deformable flange portion of the implantable device into its internal lumen. The receiving blood vessel may be either the source or the recipient of blood flow, depending on the required and existing direction of blood flow. Merely illustrative and representative of these introducer catheter based vascular bypass graft systems and techniques are U.S. Pat. Nos. 6,007,544; 5,797,920, and 5,676,670 all of which describe a catheter apparatus and methods for creating a bypass on-demand between an unobstructed and obstructed blood vessel using a deformable cuff connector and graft segment in tandem; as well as U.S. Pat. Nos. 6,036,702; 6,013,190; 6,001,124; 5,972,017; 5,941,908; and 5,931,842 which illustrate a range and variety of T-shaped, L-shaped, H-shaped, and oblique-angle graft connectors available for medical use.
A key advantage of the methods and devices described in these issued U.S. Patents is the ability to create a vascular anastomosis while maintaining high blood pressures (systemic and greater) within the receiving blood vessels. These devices and systems therefore allow the creation of the proximal anastomosis in Coronary Artery Bypass Grafting procedures (CABG) to be performed without need to exclude blood from the aorta where the site of anastomosis is to be. This in turn obviates the need for use of the cardiopulmonary bypass machine, a device (which takes over the pumping of the blood through the body while the proximal aorta is made blood pressure free); and eliminates the Aortic Side Biting Clamp, a semicircular clamp which pinches off a portion of the aorta, creating a blood pressure free pocket to which the handsewn graft attachment was previously made. Use of both the machine and the side biting clamp result in trauma to the aorta; and such trauma causes, among other things, the release of embolic debris from the aortic wall (a cause of stroke, cognitive deterioration, and other morbidities), and/or damage to the lining of the aorta which can result in separation of the layers of the aorta, resulting in dissection, a potentially lethal complication. Frequently also, the time required for surgery is shortened because intricate in-vivo suturing techniques are not required to ensure acceptable patency rates and no leakage at the handsewn anastomoses of the new grafts.
There remains, however, a long-standing and continuing need for additional improvements in bypass technique and apparatus which would allow surgeons to perform more simple multiple bypass procedures in a minimally invasive way using tubular grafts as vascular shunts; and, in particular, a need remains for a catheterless method to place one or more vein grafts or other conduits proximally to the aorta and distally to the coronary artery without using a heart-lung machine, and without stopping the heart, and without using the side biting clamp.
In addition to the foregoing difficulties, there exists also a very different medical problem in the non-vascular realm, in particular with regard to obtaining in-vivo access to a hollow organ within the body of a living subject.
Access to the interior of a hollow organ is often needed for a number of reasons, depending on the organ system. These accesses may be required to supply food substances into the stomach or small bowel in patients who are unable to eat (gastrostomy and jejunostomy, respectively); and/or to eliminate wastes or the buildup of pressure in other organs whose outlets are blocked or dysfunctional, as may occur in the obstructed urinary system (nephrostomy or cystostomy), respiratory system (tracheostomy), or the pathologically dilated cecum (proximal large bowel and cecostomy). Occasionally, a hollow organ space or body cavity is filled with infected material, and it is clinically desirable to create a communication channel allowing the infected contents to be drained rather than surgically removing the infected organ. Such a situation may occur within the gallbladder, and the communication channel so created is then called a cholecystostomy. Occasionally, a communication channel is required between hollow body cavities, such as between a cyst originating in the pancreas, and the inside of the stomach. Periodically as well, a communication channel is required into a spatial area or zone within the body, such as the peritoneal cavity, in order to instill fluids for dialysis. Thus, a number of different devices and systems now exist for the on-demand creation of these types of communication channels between hollow organs; or between body cavities and the skin surface; or between two hollow organs within the body.
It will be noted that many hollow organ surgical procedures are now performed using trocars and cannulas. Originally these devices were used for making a puncture and leaving a tube to drain fluids. As technology and surgical techniques advanced, it became possible to insert surgical instruments through the cannulas to perform invasive procedures through openings less than half an inch in diameter, whereas in the past these procedures required incisions of many inches. By using a trocar and minimizing the incision, the stress and loss of blood suffered by patients was reduced. A range and variety of trocar assemblies are known. These are represented by U.S. Pat. Nos. 4,601,710; 5,545,150; 5,122,122; 5,112,321; and 6,063,099.
Today, surgical trocars are most commonly used in laparoscopic surgery. Prior to use of the trocar, the surgeon will usually introduce a Veress needle into the patient""s abdominal cavity. The Veress needle has a stylet which permits the introduction of gas into the abdominal cavity. After the Veress needle is properly inserted, it is connected to a gas source and the abdominal cavity is insufflated to an approximate abdominal pressure of 15 mm Hg. By insufflating the abdominal cavity, pneumoperitoneum is created separating the wall of the body cavity from the internal organs.
A trocar is then typically used to puncture the body cavity. The piercing tip or obturator of the trocar is inserted through the cannula; and the cannula partially enters the body cavity through the incision made by the trocar. The obturator is then removed from the cannula. An elongated endoscope or camera may be then inserted through the cannula to view the body cavity; or surgical instruments may be inserted through the cannula to perform ligations or other procedures.
A great deal of force is often required to cause the obturator to pierce the wall of the body cavity. When the piercing tip breaks through the cavity wall, resistance to penetration ceases and the tip may reach internal organs or blood vessels, with resultant lacerations and potentially serious injury. For this reason, a variety of trocar designs have been developed with spring loaded shields surrounding the piercing tip of the obturator. Once the piercing tip of the obturator has completely pierced the body cavity wall, the resistance of the tissue to the spring loaded shield is reduced and the shield springs forward into the body cavity and covers the piercing tip. The shield thereby protects internal body organs and blood vessels from incidental contact with the piercing tip and resultant injury. Such trocars including various safety shield designs are illustrated by U.S. Pat. Nos. 4,535,773; 4,654,030; and 4,601,710; 5,104,382; 4,902,280; 5,030,206; 5,545,150; and 5,350,393.
Clearly both the realms of performing vascular bypass graft procedures and accessing the interior of a hollow organ can and would benefit from structural devices and improved surgical methods which offer simplified means for joining a prepared communication channel to a blood vessel or a hollow organ on-demand in a minimally invasive way. Moreover, were such simplified means developed such that the presently existing requirement and necessity of using a catheter or cannula is eliminated and avoided, such an improvement would be generally recognized in the medical arts as a major advance and unusual benefit to both the surgeon and his patient.
The present invention has multiple formats and applications. A first format is a catheterless, piercing introducer assembly suitable for the introduction and sutureless juncture of a prepared communication channel to the interior space of an anatomic body part within a living subject, said introducer assembly comprising:
a perforator instrument comprised of
(i) at least one elongated supporting shaft of predetermined overall dimensions and axial configuration,
(ii) a controlling handle attached at one end to said supporting shaft; and
(iii) a perforating headpiece integrally joined to the other end of said supporting shaft, said perforating headpiece comprising a perforating tip, a penetrating body, and a base aspect; and
communication channel controlling means disposed adjacent to said perforating headpiece on said supporting shaft of said perforator instrument.
A second format is a catheterless, piercing introducer assembly suitable for the introduction and sutureless juncture of a prepared communication channel to the interior space of an anatomic body part within a living subject, said introducer assembly comprising:
a perforator instrument comprised of
(i) at least one elongated supporting shaft of predetermined overall dimensions and axial configuration.
(ii) a controlling handle attached at one end to said supporting shaft; and
(iii) a perforating headpiece integrally joined to the other end of said supporting shaft, said perforating headpiece comprising a perforating tip; a penetrating body, and a base aspect.
communication channel controlling means disposed adjacent to said perforating headpiece on said supporting shaft of said perforator instrument;
a volumetric sheath having two open ends and at least one sidewall of determinable dimensions, said sheath being
(1) sized at one open end for on-demand placement adjacent to and aligned closure with said perforating headpiece of said perforator instrument,
(2) substantially annular in configuration over its axial length, and
(3) adapted for protective positioning around and volumetric spatial envelopment of at least a portion of said supporting shaft extending from said perforating headpiece of said perforator instrument, said sheath providing a protective covering for said enveloped spatial volume then surrounding said supporting shaft; and
position holding means attachable to and detachable from said volumetric sheath and said supporting shaft of said perforator instrument for holding said volumetric sheath and the enveloped spatial volume at a set position around said supporting shaft of said perforator instrument.
A third format of the present invention is a catheterless, piercing introducer assembly suitable for the introduction and sutureless juncture of a prepared communication channel to the interior space of an anatomic body part within a living subject, said introducer assembly comprising:
a perforator instrument comprised of
(i) at least one elongated supporting shaft of predetermined overall dimensions and axial configuration
(ii) a controlling handle attached at one end to said supporting shaft; and
(iii) a perforating headpiece integrally joined to the other end of said supporting shaft, said perforating headpiece comprising a perforating tip, a penetrating body, and a base aspect;
communication channel controlling means disposed adjacent to said perforating headpiece on said supporting shaft of said perforator instrument;
a volumetric sheath having two open ends and at least one sidewall of determinable dimensions, said sheath being
(1) sized at one open end for on-demand placement adjacent to and aligned closure with said perforating headpiece of said perforator instrument,
(2) substantially annular in configuration over its axial length, and
(3); adapted for protective positioning around and volumetric spatial envelopment of at least a portion of said supporting shaft extending from said perforating headpiece of said perforator instrument, said sheath providing a protective covering for said enveloped spatial volume then surrounding said supporting shaft;
position holding means attachable to and detachable from said volumetric sheath and said supporting shaft of said perforator instrument for holding said volumetric sheath and the enveloped spatial volume at a set position around said supporting shaft of said perforator instrument; and
prepared communication channel comprising
a linking connector including at least
a first portion of determined dimensions and configuration which is deformable on-demand, said first portion of said linking connector being suitable for passage through an aperture and deformation within the interior space of an anatomic body part whereby said deformation serves to secure said communication channel to the interior of the anatomic body part and places said secured communication channel in fluid flow communication with the interior space of the anatomic body part, and
a second portion of determined dimensions and configuration which is permanently joined to the sidewall of a tubular conduit such that said joining retains and secures the tubular conduit for fluid flow communication; and
a tubular conduit of fixed dimensions and configuration having two open ends and at least one internal lumen, said tubular conduit being permanently joined at one open end to said linking connector.